The present invention relates to digitizers and more specifically to an apparatus and method for automatic digitizer fault detection.
Digitizers are used in many different products to capture information. The digitizers in some products are activated by pressure from a stylus, while others are activated by finger contact.
Digitizers are subject to failure in two primary ways. First, the conductive layers may come in contact with each other due to the introduction of foreign material between the conductive layers during manufacture or the presence of conductive materials set free by wear between the conductive layers.
Second, a given conductive layer may become nonuniform. Nonuniformity in a given conductive layer may be caused by wear of the conductive layer or by tears in the conductive layer. Stress fractures in the conductive layer due to sharp bending may occur. Bending is often caused by the use of a sharp stylus or by repeated tracing of the reliefed edge of an electrode. Nonuniformity may also be caused by damage to the electrodes or scratches in the conductive layer.
Both types of failures are virtually undetectable by visual inspection. Therefore, it would be desirable to provide an apparatus and method for automatically testing digitizers.